The Year in Cardiac Imaging
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The Year in Cardiac Imaging 2009
Archive for January, 2010
Current Concepts of Integrated Coronary Physiology in the Catheterization Laboratory
Over the last 15 years, the use of invasive coronary physiology in the catheterization laboratory has demonstrated favorable outcomes for decision making in patients with intermediate single-vessel stenoses, complex bifurcation and ostial branch stenoses, multivessel coronary artery disease, and left main stenoses. A recent large multicenter study (FAME [FFR versus Angiography for Multivessel Evaluation]) found that a physiologically-guided approach was superior to the standard angiographically-guided approach for percutaneous revascularization in patients with multivessel coronary artery disease. This review addresses selected pertinent concepts and studies supporting the integration of coronary physiology in the catheterization laboratory for optimal patient outcomes.
Premature Aortic Atherosclerosis in Systemic Lupus Erythematosus: A Controlled Transesophageal Echocardiographic Study
OBJECTIVES: Premature carotid and coronary atherosclerosis are common in systemic lupus erythematosus (SLE), but data on aortic atherosclerosis (AA) are limited. Thus, using multiplane transesophageal echocardiography (TEE), we sought to determine the prevalence and clinical correlates of AA in patients with SLE.
METHODS: Forty-seven patients with SLE (44 women, age 38 +/- 12 years) and 21 healthy controls (19 women, age 34 +/- 12 years) underwent clinical and laboratory evaluations and TEE to assess AA defined as aortic intima media thickness (IMT) > 0.86 mm or plaques as > 50% focal IMT as compared with surrounding walls. TEE studies were interpreted by an experienced observer unaware of subjects’ clinical data.
RESULTS: The prevalence of abnormal aortic IMT, plaques, or both lesions was higher in patients as compared to controls (37%, 23%, and 43% vs 14%, 0%, and 14%, respectively, all p <0.02). In patients, age at diagnosis of SLE was the only positive independent predictor of AA [OR 1.12 per year from diagnosis of SLE, 95% confidence interval (CI) 1.04-1.19, p = 0.001] and cyclophosphamide therapy was the only negative independent predictor of AA (OR 0.186, 95% CI 0.153-0.95, p = 0.04, equivalent to 5.4 times less likely to develop AA).
CONCLUSIONS: AA is common in young patients with SLE and is predicted by a later age at diagnosis of SLE, but is negatively correlated with cyclophosphamide therapy. Thus, early diagnosis and more aggressive immunosuppressive therapy may be required to decrease the development and progression of atherosclerosis in patients with SLE.
PMID: 19955049
Volumetric Quantification of Myocardial Perfusion Using Analysis of Multi-Detector Computed Tomography 3D Datasets: Comparison With Nuclear Perfusion Imaging
OBJECTIVES: Although the ability of multi-detector computed tomography (MDCT) to detect perfusion abnormalities associated with acute and chronic myocardial infarction (MI) has been demonstrated, this methodology is based on visual interpretation of selected 2D slices. We sought to develop a new technique for quantitative volumetric analysis of myocardial perfusion from 3D datasets and test it against resting nuclear myocardial perfusion imaging (NMPI) reference.
METHODS: We studied 44 patients undergoing CTCA: a control group of 15 patients and a study group of 29 patients. MDCT datasets acquired for CTCA were analyzed using custom software designed to: (1) generate bull’s eye display of myocardial perfusion and (2) calculate a quantitative index of extent and severity of perfusion abnormality, Q(H), for 16 volumetric myocardial segments. Visual interpretation of MDCT-derived bull’s eyes was compared with rest NMPI scores using kappa statistics of agreement on a coronary territory and patient basis. Quantitative MDCT perfusion data were correlated with rest NMPI summed scores and used for objective detection of perfusion defects.
RESULTS: Visual analysis of MDCT-derived bull’s eyes accurately detected perfusion defects in agreement with NMPI (kappa = 0.70 by territory; 0.79 by patient). Quantitative data were in good agreement with NMPI, as reflected by: (1) correlation of 0.87 (territory) and 0.84 (patient) between summed Q(H) and NMPI scores, (2) area under ROC curve 0.87 with sensitivity of 0.79-0.92, specificity 0.83-0.91, and accuracy 0.83-0.89 for objective detection of abnormalities.
CONCLUSIONS: Our new technique for volumetric analysis of 3D MDCT images allows accurate objective detection of perfusion defects. This perfusion information can be obtained without additional radiation or contrast load, and may aid in elucidating the significance of coronary lesions.
PMID: 19711083
Segmental Heterogeneity of Vasa Vasorum Neovascularization in Human Coronary Atherosclerosis
OBJECTIVES: Our aim was to investigate the role of coronary vasa vasorum (VV) neovascularization in the progression and complications of human coronary atherosclerotic plaques. Accumulating evidence supports an important role of VV neovascularization in atherogenesis and lesion location determination in coronary artery disease. VV neovascularization can lead to intraplaque hemorrhage, which has been identified as a promoter of plaque progression and complications like plaque rupture. We hypothesized that distinctive patterns of VV neovascularization and associated plaque complications can be found in different stages of human coronary atherosclerosis.
METHODS: Hearts from 15 patients (age 52 ± 5 years, mean ± SEM) were obtained at autopsy, perfused with Microfil (Flow Tech, Inc., Carver, Massachusetts), and subsequently scanned with micro-computed tomography (CT). The 2-cm segments (n = 50) were histologically classified as either normal (n = 12), nonstenotic plaque (<50% stenosis, n = 18), calcified (n = 10) or noncalcified (n = 10) stenotic plaque. Micro-CT images were analyzed for VV density (number/mm2), VV vascular area fraction (mm2/mm2), and VV endothelial surface fraction (mm2/mm3). Histological sections were stained for Mallory’s (iron), von Kossa (calcium), and glycophorin-A (erythrocyte fragments) as well as endothelial nitric oxide synthase, vascular endothelial growth factor, and tumor necrosis factor-alpha.
RESULTS: VV density was higher in segments with nonstenotic and noncalcified stenotic plaques as compared with normal segments (3.36 ± 0.45, 3.72 ± 1.03 vs. 1.16 ± 0.21, p < 0.01). In calcified stenotic plaques, VV spatial density was lowest (0.95 ± 0.21, p < 0.05 vs. nonstenotic and noncalcified stenotic plaque). The amount of iron and glycophorin A was significantly higher in nonstenotic and stenotic plaques as compared with normal segments, and correlated with VV density (Kendall-Tau correlation coefficient 0.65 and 0.58, respectively, p < 0.01). Moreover, relatively high amounts of iron and glycophorin A were found in calcified plaques. Further immunohistochemical characterization of VV revealed positive staining for endothelial nitric oxide synthase and tumor necrosis factor-alpha but not vascular endothelial growth factor.
CONCLUSIONS: Our results support a possible role of VV neovascularization, VV rupture, and intraplaque hemorrhage in the progression and complications of human coronary atherosclerosis.
Comparison of Aortic Root Dimensions and Geometries Before and After Transcatheter Aortic Valve Implantation by 2-and 3-Dimensional Transesophageal Echocardiography and Multislice Computed Tomography
OBJECTIVES: 3D transesophageal echocardiography (TEE) may provide more accurate aortic annular and left ventricular outflow tract (LVOT) dimensions and geometries compared with 2D TEE. We assessed agreements between 2D and 3D TEE measurements with multislice computed tomography (MSCT) and changes in annular/LVOT areas and geometries after transcatheter aortic valve implantations (TAVI).
METHODS: Two-dimensional circular (
xr2), 3D circular, and 3D planimetered annular and LVOT areas by TEE were compared with “gold standard” MSCT planimetered areas before TAVI.
RESULTS: Mean MSCT planimetered annular area was 4.65±0.82 cm2 before TAVI. Annular areas were underestimated by 2D TEE circular (3.89±0.74 cm2, P<0.001), 3D TEE circular (4.06±0.79 cm2, P<0.001), and 3D TEE planimetered annular areas (4.22±0.77 cm2, P<0.001). Mean MSCT planimetered LVOT area was 4.61±1.20 cm2 before TAVI. LVOT areas were underestimated by 2D TEE circular (3.41±0.89 cm2, P<0.001), 3D TEE circular (3.89±0.94 cm2, P<0.001), and 3D TEE planimetered LVOT areas (4.31±1.15 cm2, P<0.001). Three-dimensional TEE planimetered annular and LVOT areas had the best agreement with respective MSCT planimetered areas. After TAVI, MSCT planimetered (4.65±0.82 versus 4.20±0.46 cm2, P<0.001) and 3D TEE planimetered (4.22±0.77 versus 3.62±0.43 cm2, P<0.001) annular areas decreased, whereas MSCT planimetered (4.61±1.20 versus 4.84±1.17 cm2, P=0.002) and 3D TEE planimetered (4.31±1.15 versus 4.55±1.21 cm2, P<0.001) LVOT areas increased. Aortic annulus and LVOT became less elliptical after TAVI.
CONCLUSIONS: Before TAVI, 2D and 3D TEE aortic annular/LVOT circular geometric assumption underestimated the respective MSCT planimetered areas. After TAVI, 3D TEE and MSCT planimetered annular areas decreased as it assumes the internal dimensions of the prosthetic valve. However, planimetered LVOT areas increased due to a more circular geometry.
PMID: 19920027
Prospective and Retrospective ECG-gating for CT Coronary Angiography Perform Similarly Accurate at Low Heart Rates
OBJECTIVE: To compare, in patients with suspicion of coronary artery disease (CAD) and low heart rates, image quality, diagnostic performance, and radiation dose values of prospectively and retrospectively electrocardiography (ECG)-gated dual-source computed tomography coronary angiography (CTCA) for the diagnosis of significant coronary stenoses.
METHODS: Two-hundred consecutive patients with heart rates <70bpm were retrospectively enrolled; 100 patients undergoing prospectively ECG-gated CTCA (group 1) and 100 patients undergoing retrospectively-gated CTCA (group 2). Coronary artery segments were assessed for image quality and significant luminal diameter narrowing. Sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and accuracy of both CTCA groups were determined using conventional catheter angiography (CCA) as reference standard. Radiation dose values were calculated.
RESULTS: Both groups were comparable regarding gender, body weight, cardiovascular risk profile, severity of CAD, mean heart rate, heart rate variability, and Agatston score (all p>0.05). There was no significant difference in the rate of non-assessable coronary segments between group 1 (1.6%, 24/1404) and group 2 (1.4%, 19/1385; p=0.77); non-diagnostic image quality was significantly (p<0.001) more often attributed to stair step artifacts in group 1. Segment-based sensitivity, specificity, PPV, NPV, and accuracy were 98%, 98%, 88%, 100%, and 100% among group 1; 96%, 99%, 90%, 100%, and 98% among group 2, respectively. Parameters of diagnostic performance were similar (all p>0.05). Mean effective radiation dose of prospectively ECG-gated CTCA (2.2+/-0.4mSv) was significantly (p<0.0001) smaller than that of retrospectively ECG-gated CTCA (8.1+/-0.6mSv).
CONCLUSIONS: Prospectively ECG-gated CTCA yields similar image quality, performs as accurately as retrospectively ECG-gated CTCA in patients having heart rates <70bpm while being associated with a lower mean effective radiation dose.
PMID: 20079993
Incremental Value of Adenosine-Induced Stress Myocardial Perfusion Imaging With Dual-Source CT at Cardiac CT Angiography
OBJECTIVES: First, to assess the feasibility of a protocol involving stress-induced perfusion evaluated at computed tomography (CT) combined with cardiac CT angiography in a single examination and second, to assess the incremental value of perfusion imaging over cardiac CT angiography in a dual-source technique for the detection of obstructive coronary artery disease (CAD) in a high-risk population.
METHODS: Institutional review board approval and informed patient consent were obtained before patient enrollment in the study. The study was HIPAA compliant. Thirty-five patients at high risk for CAD were prospectively enrolled for evaluation of the feasibility of CT perfusion imaging. All patients underwent retrospectively electrocardiographically gated (helical) adenosine stress CT perfusion imaging followed by prospectively electrocardiographically gated (axial) rest myocardial CT perfusion imaging. Analysis was performed in three steps: (a)Coronary arterial stenoses were scored for severity and reader confidence at cardiac CT angiography, (b)myocardial perfusion defects were identified and scored for severity and reversibility at CT perfusion imaging, and (c)coronary stenosis severity was reclassified according to perfusion findings at combined cardiac CT angiography and CT perfusion imaging. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of cardiac CT angiography before and after CT perfusion analysis were calculated.
RESULTS: With use of a reference standard of greater than 50% stenosis at invasive angiography, all parameters of diagnostic accuracy increased after CT perfusion analysis: Sensitivity increased from 83% to 91%; specificity, from 71% to 91%; PPV, from 66% to 86%; and NPV, from 87% to 93%. The area under the receiver operating characteristic curve increased significantly, from 0.77 to 0.90 (P < .005).
CONCLUSIONS: A combination protocol involving adenosine perfusion CT imaging and cardiac CT angiography in a dual-source technique is feasible, and CT perfusion adds incremental value to cardiac CT angiography in the detection of significant CAD.
PMID: 20093513
Tissue Doppler Image-Derived Measurements During Isovolumic Contraction Predict Exercise Capacity in Patients With Reduced Left Ventricular Ejection Fraction
OBJECTIVES: We explored the incremental value of quantification of tissue Doppler (TD) velocity during the brief isovolumic contraction (IVC) phase of the cardiac cycle for the prediction of exercise performance in patients referred for cardiopulmonary exercise testing (CPET). Experimental studies have shown that rapid left ventricular (LV) shape change during IVC is essential for optimal onset of LV ejection. However, the incremental value of measuring IVC velocities in clinical settings remains unclear.
METHODS: A total of 82 subjects (age 53 ± 14 years, 56 men) were studied with echocardiography and CPET. Reduced LV ejection fraction (EF) (EF <50%) was present in 38 (46%) subjects. Pulsed-wave annular TD velocities were averaged from the LV lateral and septal annulus during isovolumic contraction (IVCa), ejection, isovolumic relaxation, and early and late diastole (Aa) and compared with peak oxygen consumption (VO2) and percentage of the predicted peak VO2 (% predicted peak VO2) obtained from CPET.
RESULTS: Patients with reduced EF had lower IVCa (6.3 vs. 4.5 cm/s, p = 0.04), ejection (7.7 vs. 5.5 cm/s, p < 0.001), and Aa velocities (7.9 vs. 6.6 cm/s, p = 0.04). Similarly, % predicted peak VO2 was lower in patients with reduced EF (52.9% vs. 73.1%, p < 0.001) and correlated with the variations in IVCa (r = 0.7, p = 0.001). Multivariate analysis of 2-dimensional and Doppler variables in the presence of reduced LV EF revealed only IVCa and Aa as independent predictors of % predicted peak VO2 (r2 = 0.612, p = 0.02 for IVCa and p = 0.009 for Aa). The overall performance of IVCa in the prediction of exercise capacity was good (area under the curve = 0.86, p < 0.001).
CONCLUSIONS: Assessment of TD-derived IVC and atrial stretch velocities provide independent prediction of exercise capacity in patients with reduced LV EF. Assessment of LV pre-ejectional stretch and shortening mechanics at rest may be useful for determining the myocardial functional reserve of patients with reduced EF.
Viability Assessment With Global Left Ventricular Longitudinal Strain Predicts Recovery of Left Ventricular Function After Acute Myocardial Infarction
OBJECTIVES: The extent of viable myocardial tissue is recognized as a major determinant of recovery of left ventricular (LV) function after myocardial infarction. In the current study, the role of global LV strain assessed with novel automated function imaging (AFI) to predict functional recovery after acute infarction was evaluated.
METHODS: A total of 147 patients (mean age, 61±11 years) admitted for acute myocardial infarction were included. All patients underwent 2D echocardiography within 48 hours of admission.
RESULTS: Significant relations were observed between baseline AFI global LV strain and peak level of troponin T (r=0.64), peak level of creatine phosphokinase (r=0.62), wall motion score index (r=0.52), and viability index assessed with single-photon emission computed tomography (r=0.79). At 1-year follow-up, LV ejection fraction was reassessed. Patients with absolute improvement in LV ejection fraction >5% at 1-year follow-up (n=70; 48%) had a higher (more negative) baseline AFI global LV strain (P<0.0001). Baseline AFI global LV strain was a predictor for change in LV ejection fraction at 1-year follow-up. A cutoff value for baseline AFI global LV strain of –13.7% yielded a sensitivity of 86% and a specificity of 74% to predict LV functional recovery at 1-year follow-up.
CONCLUSIONS: AFI global LV strain early after acute myocardial infarction reflects myocardial viability and predicts recovery of LV function at 1-year follow-up.
PMID: 19820202
Left Ventricular Diastolic Function in Type 2 Diabetes Mellitus: Prevalence and Association With Myocardial and Vascular Disease
OBJECTIVES: Although type 2 diabetes mellitus is a risk factor for developing congestive heart failure, the mechanism leading to heart failure is unclear. We examined the prevalence of left ventricular (LV) systolic and diastolic dysfunction in patients with type 2 diabetes mellitus in relation to vascular function and myocardial perfusion.
METHODS: A prospective observational study of 305 patients with type 2 diabetes mellitus (diabetes duration, 4.5±5.3 years) referred consecutively to a diabetes clinic were screened for LV systolic and diastolic function by echocardiography. Vascular function was estimated using noninvasive estimation of pulse pressure, carotid arterial compliance, total arterial compliance, and valvulo-arterial impedance.
RESULTS: The prevalences of LV diastolic dysfunction and left atrial (LA) volume index >32 mL/m2 were 40% and 32%, respectively. The prevalence of myocardial ischemia on myocardial perfusion scintigraphy was more frequent in patients with grade 2 diastolic dysfunction and LA volume index >32 mL/m2 compared with those having normal or grade 1 diastolic dysfunction (P=0.002) or LA volume index < 32 mL/m2 (P<0.001), respectively. Predictors of grade 2 diastolic dysfunction and LA dilation were summed stress score on myocardial perfusion scintigraphy, total arterial compliance, and valvulo-arterial impedance, whereas pulse pressure and carotid arterial compliance were not, after adjusting for age, sex, and diabetes duration. On multivariable modeling, summed stress score (P<0.001) and valvulo-arterial impedance (P=0.027) remained predictors of grade 2 diastolic dysfunction, and only summed stress score (P<0.001) was a predictor of LA dilation.
CONCLUSIONS: Abnormal LV filling is closely associated with abnormal myocardial perfusion on myocardial perfusion scintigraphy, whereas the association of LV filling with vascular function is less prominent.
PMID: 19846730
Cardiac CT Angiography for the Diagnosis of Mitral Valve Prolapse: Comparison with Echocardiography
OBJECTIVES: To evaluate the diagnostic performance of coronary computed tomographic (CT) angiography for the diagnosis of mitral valve prolapse (MVP).
METHODS: The retrospective case-controlled multicenter study protocol was approved by the institutional review boards. The U.S. part of the study was HIPAA compliant. One hundred twelve patients who underwent electrocardiographically gated 64-section coronary CT angiography (n = 60) or dual-source coronary CT angiography (n = 52) and transthoracic echocardiography (TTE) were included. Fifty-three patients with MVP were matched for age and sex with 59 patients without MVP. CT images were analyzed on three-, two-, and four-chamber (CH) views by two independent observers. MVP was defined as a greater than 2-mm displacement of leaflets below the annulus plane and was subclassified as “billowing” (bowing) or “flail leaflet” (free leaflet margin displacement). Leaflet thickness was measured and defined as thickened if it was greater than 2 mm.
RESULTS: The diagnostic performance of CT when three- and two-CH views were combined for the diagnosis of MVP was as follows: sensitivity, 96%; specificity, 93%; positive predictive value (PPV), 93%; and negative predictive value, 96%. On four-CH views, the excursion of billowing was higher than it was on three-CH views (P <.001), and the PPV of the four-CH view for diagnosis of MVP was 89%. The correlation between CT and TTE for excursion of billowing was high (r = 0.80-0.91). In a subset of 32 patients, the agreement between CT and TTE for differentiation of billowing (n = 13) and flail leaflet (n = 2) was 100%. Leaflet thickening was more prevalent in patients with MVP than it was in those without (71% vs 20%, P <.001), and correlation with TTE was good (r = 0.81 [anterior leaflet] and 0.77 [posterior leaflet]).
CONCLUSIONS: The combined use of three- and two-CH views allows an accurate diagnosis of MVP at coronary CT angiography.
PMID: 20093510
Age-Modification of Lipoprotein, Lipid, and Lipoprotein Ratio-Associated Risk for Coronary Artery Calcium (From the Multi-Ethnic Study of Atherosclerosis [MESA])
OBJECTIVES: Although abnormal lipoproteins and lipoprotein ratios are powerful risk factors for clinical cardiovascular events, these associations are stronger in younger than in older subjects. Whether age modifies the relation of lipoproteins and lipoprotein ratios to the relative risk of subclinical cardiovascular disease (CVD), as assessed by coronary artery calcium (CAC) scores, has not been examined in a contemporary, multiethnic cohort.
METHODS: We performed multivariate relative risk regression analyses to determine the relative risks for associations of lipoproteins and lipoprotein ratios with prevalent CAC in participants in Multi-Ethnic Study of Atherosclerosis (MESA). The participants were community-dwelling adults aged 45 to 84 years without clinically apparent CVD at baseline. We excluded those taking lipid-lowering therapy (15%) and stratified the results by decades of age.
RESULTS: A total of 5,092 participants met the inclusion criteria. In the fully adjusted models, per SD of low-density lipoprotein, the age-stratified, adjusted relative risk for CAC was 1.17 (95% confidence interval [CI] 1.07 to 1.28) for those aged 45 to 84 years but was 1.05 (95% CI 1.01 to 1.10) for those aged 75 to 84 years (p-interaction = 0.12). The relative risk per SD of total/high-density lipoprotein cholesterol ratio was 1.20 (95% CI 1.12 to 1.29) for those aged 45 to 54 years but only 1.04 (95% CI 1.00 to 1.09) for those aged 75 to 84 years (p-interaction <0.001). The lipoproteins levels and lipoprotein ratios were associated with increased relative risks for CAC across all age categories. However, these associations were markedly attenuated by age.
CONCLUSIONS: In conclusion, abnormal lipoprotein levels in middle age are a powerful risk factor for early atherosclerosis, as manifested by prevalent CAC.
Use of Balloon Aortic Valvuloplasty to Size the Aortic Annulus Before Implantation of a Balloon-Expandable Transcatheter Heart Valve
OBJECTIVES: Our aim was to describe the use of balloon aortic valvuloplasty (BAV) to select proper transcatheter heart valve (THV) size. Transesophageal echocardiogram (TEE) measurement alone of the aortic annulus may not be adequate to select a THV size. BAV can more accurately size the aortic annulus. We report our experience using this strategy in patients undergoing THV implantation.
METHODS: Twenty-seven patients underwent sizing of the aortic annulus by BAV and TEE. We implanted the minimal THV size that was greater than the annulus measured by BAV.
RESULTS: The annulus measured by TEE was 21.3 ± 1.6 mm and by BAV was 22.6 ± 1.8 mm (p < 0.001). The number of balloon inflations was 2.7 ± 0.7 (range 2 to 4), and the balloon sizes used were 22.0 ± 1.8 mm (range 20 to 25 mm). Fourteen patients (52%) required upsizing of the initial balloon suggested by TEE; rapid pacing duration was 8 ± 1.3 s (range 6 to 11 s). No change in aortic insufficiency or hemodynamic instability occurred with BAV. Fifteen patients (56%) received a 23-mm THV; 12 patients a 26-mm THV. No coronary occlusion, annular damage, or THV embolization occurred. Paravalvular leak was grade 
1 in all patients. In 7 patients (26%), balloon sizing resulted in selection of a specific THV size that could not be done by TEE alone.
CONCLUSIONS: BAV sizing of the aortic annulus is safe and is an important adjunct to TEE when selecting THV size. Implanting the minimal THV greater than the BAV annulus size resulted in no adverse events. These data suggest that use of BAV for THV selection may improve the safety and efficacy of THV implantation
Natural History and Expansive Clinical Profile of Stress (Tako-Tsubo) Cardiomyopathy
OBJECTIVES: This study was designed to define more completely the clinical spectrum and consequences of stress cardiomyopathy (SC) beyond the acute event. Stress cardiomyopathy is a recently recognized condition characterized by transient cardiac dysfunction with ventricular ballooning.
METHODS: Clinical profile and outcome were prospectively assessed in 136 consecutive SC patients.
RESULTS: Patients were predominantly women (n = 130; 96%), but 6 were men (4%). Ages were 32 to 94 years (mean age 68 ± 13 years); 13 (10%) were 
50 years of age. In 121 patients (89%), SC was precipitated by intensely stressful emotional (n = 64) or physical (n = 57) events, including 22 associated with sympathomimetic drugs or medical/surgical procedures; 15 other patients (11%) had no evident stress trigger. Twenty-five patients (18%) were taking beta-blockers at the time of SC events. Three diverse ventricular contraction patterns were defined by cardiovascular magnetic resonance (CMR) imaging, usually with rapid return to normal systolic function, although delayed >2 months in 5%. Right and/or left ventricular thrombi were identified in 5 patients (predominantly by CMR imaging), including 2 with embolic events. Three patients (2%) died in-hospital and 116 (85%) have survived, including 5% with nonfatal recurrent SC events. All-cause mortality during follow-up exceeded a matched general population (p = 0.016) with most deaths occurring in the first year.
CONCLUSIONS: In this large SC cohort, the clinical spectrum was heterogeneous with about one-third either male, 50 years of age, without a stress trigger, or with in-hospital death, nonfatal recurrence, embolic stroke, or delayed normalization of ejection fraction. Beta-blocking drugs were not absolutely protective and SC was a marker for increased noncardiac mortality. These data support expanded management and surveillance strategies including CMR imaging and consideration for anticoagulation.
